Suggestions:
System sets the reason code by default in the Purchase return for each item. This code is populated with the value ‘SRNEX’. So it is very convenient for the users, they don’t have to enter the reason code manually.
In Purchase return, item details screen, once the users enter the line number then the details get populated. Details such as item details, location details, tax details etc. On the entering of return quantity, reason code should get populated as value ‘SRNEX’ if the supplier is channel partner.
If Purchase return made manually then Reason code not set by default in system. It is non mandatory field and can be selected from pophelp. Reason code is used to store additional information. When Purchase return made from channel partner return process then reason code will set automatically